IGNIS March 2014 | 页面 4

Librophilia Introducing Geology: A Guide to The World of Rocks by Graham Park Our world is made of rock. Although much of the Earth’s surface is covered by vegetation, concrete or water, if one digs down far enough solid rock will always be found. Those who live in a landscape where rock outcrops are obvious will have wondered about the kind of rocks they are looking at and how they came to be where they are now. This introductory book explains in simple terms what geology can tell us about the world. Many objects of great beauty and which excite our curiosity, such as crystals or fossils, are to be found by examining rocks. Those searching for and examining such objects gain much more by knowing how and when they originated. In particular fossils, whilst interesting in themselves, tell us from their context in geological time of biological evolution and these clues give an insight into the origins of life on earth. Copiously illustrated this book is intended for those whose interest in geology has been awakened, perhaps by media coverage of earthquakes or dinosaurs and want to know more. Technical terms are kept to a minimum and are explained in a glossary. Geology: The Key Ideas (Teach Yourself) by David Rothery Understand Geology is a definitive introduction to the nature and workings of the Earth. Extensively illustrated it covers everything from earthquakes and plate tectonics to the formation of rocks and minerals. With clear explanations of complex geological processes, and a glossary of specialist terms, this book will give you a new understanding of the planet we live on. NOT GOT MUCH TIME? One, five and ten-minute introductions to key principles to get you started. AUTHOR INSIGHTS Lots of instant help with common problems and quick tips for success, based on the author’s many years of experience. EXTEND YOUR KNOWLEDGE Extra online articles at www.teachyourself.com to give you a richer understanding. THINGS TO REMEMBER Quick refreshers to help you remember the key facts. Gemstones of The World by Walter Schumann Newly published in a fifth edition, this definitive guide takes the mystery out of appreciating, buying and selling gemstones. It covers everything from the romance and history of more than 1,800 gemstones to their geographic locations; scientific, physical and colour properties; and the way they are formed, structured and mined. The book also fully covers the optical features of gems - light and colour, luminescence, refraction and inclusions - and key information about the densities and chemical elements of each stone, with fascinating details on different cuts, polishing, gems, hardness, cleavage, classification, trade names, rarity and more. There are also many charts and diagrams as well as magnificent colour photographs of the stones with data about them on the facing page. If you want only one book on gemstones in your library, this would be the one! 4 | FUSE Did you know? hh Naturally forming chalk is actually made up of millions of little fossils called cocoliths, which were the round “shells” of animals called cocolithophores. hh The study of earthquakes started in at least 350 BC when Aristotle noticed that soft grounds shake more than the hard rocky ground. hh Mauna Loa, the largest volcano on Earth, is located in Hawaii Volcanoes National Park, Hawaii. Mauna Loa is over 30,000-ft tall from the sea floor to the summit, that’s taller than Mt. Everest! hh Flint is thought to be re-crystallised silica from sea sponges from the Cretaceous period hh Looking at the bulk composition of the Earth the most common mineral is generally regarded as olivine since the mantle makes up the bulk of the Earth and olivine makes up the bulk of the mantle. hh Diamonds are not actually forever! They are unstable on the Earth’s surface and will eventually degrade into a stable form of carbon (graphite). hh Some minerals fluoresce under UV light due to impurities known as activators. The activator absorbs ultraviolet radiation, and in reaction emits a combination of visible light (colour). Sometimes the activator electrons get stuck in their high-energy state and the mineral will continue to glow after the UV light is switched off. This is called phosphorescence. Common minerals that fluoresce are Calcite and Fluorite. hh Minerals are defined by being an inorganic, naturally forming, substance with a definite chemical composition and usually a definite crystal structure. All of which ice satisfies. So by definition, ice is a mineral. hh The deepest place is near the Mariana Islands in the Pacific. It is 11,033 meters (36,201 feet) below sea level. If Mount Everest were placed inside of this trench, it would disappear. The deepest part of the trench is named Vitjazdepth. The trench was formed when the Pacific plate collided with the Philippine plate, which also resulted in the formation of the nearby island Guam. hh Mount Kilimanjaro, the giant mountain in East Africa is actually a dormant volcano. It is 19,340 feet (5,895 metres) high at the peak. On the slopes of Mount Kilimanjaro, at c9,000 feet (2,800 metres) the only animals around Kilimanjaro are moles, rats and birds of prey. At higher altitudes there is just the odd spider that can reach the summit and survive the freezing temperatures! hh Diamonds are older than the dinosaurs. The youngest natural diamond is over 900 million years old! hh The Magnetic North Pole is not in the same location as the real North Pole. In actuality it is located near Ellesmere Island in Canada. But on top of that, it has moved throughout history and is currently moving at about 40 miles per year. It even flips with the South Pole on a regular basis every ~0.8 million years. hh Japan \